Postbiotics as a functional supplement to develop cell culture media for cultivated meat production

The development of sustainable, cost-effective, and animal-free culture media remains a critical challenge in the large-scale commercialization of cultivated meat. Fetal bovine serum (FBS), the most widely used supplement in cell culture, presents ethical concerns and significantly increases production costs. In this study, we investigated postbiotic compounds-specifically microbial biomass lysates and cell-free supernatants from Lacticaseibacillus rhamnosus, Bacillus subtilis, and Saccharomyces boulardii as potential alternatives to FBS for supporting the growth and differentiation of bovine satellite cells (BSCs). Metabolomic profiling (GC-MS and LC-MS/MS) revealed that L. rhamnosus biomass lysates were enriched in growth-promoting metabolites including 5-aminolevulinic acid, cis-4-hydroxy-D-proline, and trans-4-hydroxy-L-proline. Notably, treatments with low concentrations (5 μg/mL) of L. rhamnosus lysate significantly enhanced BSC proliferation and facilitated myotube formation, confirming its functional efficacy. Conversely elevated levels of short-chain fatty acids (SCFAs) in postbiotic preparations correlated with reduced cell proliferation, likely due to SCFA-induced apoptotic effects in immortalized cells. Spearman correlation analysis also revealed a strong inverse association between total SCFA content of postbiotics and BSC viability, highlighting composition-dependent functional effects. These findings provide mechanistic insight into the bioactivity of postbiotic-derived metabolites and establish a foundation for serum-free, scalable media formulations in cellular agriculture and cultivated meat production.